The present invention relates generally to a coil, skein or bunch of strand-like stock, for example, wire, insulated or non-insulated cable, glass fiber or the like, and more particularly to an improved method for producing such a coil and apparatus for carrying out the improved method.
Frequently during the processing of strand-like stock, such as wire, the need arises for further processing of the wire that cannot be carried out at the same coil location, often, not even in the same plant, in which the wire itself was manufactured. The strand-like stock must then be prepared in a suitable way for transport and brought to the location where the further processing occurs. Several problems or disadvantages have arisen as result of the preparation required for transportation of the stock. Commonly, the winding material is wound on winding cores or spools for transportation together with the wound material. Therefore, a large number of spools must be stored at the corresponding locations or plants, which requires a considerable investment cost. Further, considerable costs arise because the empty spools must be transported back from the processing point to the original production plant. Moreover, the spools also increase the transport weight of the wound stock, which produces an increase in transportation costs.
In order to avoid the aforementioned problems and disadvantages, a need has developed in the industry for strand-like stock, such as wire or cable, that is not wound on spools, but rather transported and delivered as skeins or bunches that substantially are comprised only of the actual strand-like material itself and possibly a cover or other packaging for the coil. This type of coil is usually referred to as a one-way packaged coil.
A method for producing a one-way packaged coil is disclosed in DE-OS 3520195. In this known method a cone-shaped winding spool is used. The strand-like stock is wound on the cone-shaped spool in individual layers parallel to one another. An adhesive then is provided, which binds the individual windings and layers to one another. When further processing occurs, the wire is unwound from the inside.
There are number of serious disadvantages that result from employing this method and the coil that results therefrom. First of all, use of an adhesive in the production of the coil is disadvantageous because it makes the method complicated and expensive. In addition, the adhesive can disrupt further processing of the coil and, therefore, in some circumstances it must initially be removed. Furthermore, entanglement of the wire layers can occur, despite the use of adhesive, especially, when approaching the end of the unwinding process as the adhesive forces between the individual layers degenerate, resulting in several windings coming loose at once.
The invention is directed to a method for producing a coil that can be carried out more simply and inexpensively than heretofore possible, while at the same time providing a stable coil that can be transported and processed without incurring the disadvantages and problems of the prior art. Advantageous apparatus for carrying out the method of the invention and for unwinding a coil also are disclosed.